(1) Technical Field
The present invention relates to a system for forming a three-dimensional holographic display. More specifically, to a three-dimensional holographic display system that allows a user to view the hologram from a plurality of points and angles, up to 360 degrees around the display.
(2) Description of Related Art
The world in which we live is a three-dimensional (3D) world. However, most of the images created are only in two dimensions (2D). In an attempt to improve upon traditional images, several innovations have been conceived to more accurately represent our 3D environment. By way of example, 3D television shows and theme park attractions have been created. Unfortunately, however, a viewer must wear special glasses to experience these 3D images. Such 3D image displays are achieved by simultaneously projecting two parallax views acquired from a 3D object onto a screen. In such a display, viewers must wear a polarization goggle to view the 3D images. Recently, many new technologies have been developed that have removed the need for glasses.
3D display companies are only starting to develop prototypes for specific businesses that focus on entertainment and product design, but these prototypes are not practical for general applications and average consumers. Following are several exemplary companies that are developing various 3D displays.
Actuality Systems, Inc., located at 213 Burlington Road, Bedford, Mass. 01730, U.S.A., developed the Perspecta® display. The Perspecta® display works by projecting several thousand 2D images per second onto a rotating screen using Texas Instrument's digital micro-mirror device (DMD) chips. Texas Instrument is located at 13532 N. Central Expressway, M/S 3807, Dallas, Tex. 75243-1108, U.S.A. Similar to television, the eye fuses these images together to create a seamless image. The raster-scan display renders resolution, binary images at 768×768 pixels. Each scan projects 198 images, approximately 1.1 images per degree of rotation, and 24 scans per second. The DMDs can project binary images with 5 kilohertz (kHz) speed. However, Perspecta® display can only render 3-bit color (with 3 DMD chips) and limited gray scale images.
Deep Video Imaging, Ltd. has developed a 3D display called Actualdepth. Deep Video Imaging, Ltd. is located at Airport Road RD2, Mystery Creek, Hamilton, 02021, New Zealand. Actualdepth uses two layers of liquid crystal display (LCD) panels to create the illusion of depth. The company appears to be targeting kiosks and point of purchase displays instead of computer desktop applications, like some of the other developers.
Dimension Technologies, Inc. (DTI) has developed liquid crystal displays (LCD's) that display 3D images without the need for imaging glasses. DTI is located at 315 Mt. Read Boulevard, Rochester, N.Y. 14611, U.S.A. The technical term for DTI's technology is “autostereoscopic, 3D imaging”, i.e., placing a single active substrate between the LCD and its back lighter. When turned on it allows the display to show real 3D images by creating light lines. These light lines are placed behind a conventional LCD panel, creating what DTI calls a Virtual Window™. The Virtual Window™ is essentially an LCD screen that gives the appearance of a 3D image.
Dresden 3D GmbH, now owned by SeeReal Technologies, creates a 3D display on an LCD screen. SeeReal Technologies is located at Blasewitzer Straβe 43, 01307 Dresden, Germany. The Dresden 3D Display (D4D) is an 18.1″ thin-film transistor (TFT) LCD, similar to the largest Virtual Window™ by DTI. The D4D includes eye tracking that allows viewers to have the freedom to view 3D images from various angles by tracking the location of their head and changing the aspect of the hologram respectively. In addition to operating as a primary monitor, Dresden is also marketing the D4D as a secondary display that will compliment a normal monitor. Because of this, Dresden optionally bundles a FireGL 3 graphics board with the D4D. The FireGL 3 is capable of driving two displays simultaneously. A keyboard shortcut allows a user to toggle the 3D display on and off when two displays are used. Another feature of the FireGL 3 is that any OpenGL program can be set to output stereo 3D images to the D4D. The FireGL 3 is a high-end graphics card created by ATI technologies, Inc., located at 1 Commerce Valley Drive East, Markham, Ontario, Canada L3T 7X6.
Holografika produces the HoloVizio line of displays. Holografika is located at Pf. 100, Budapest, H-1704, Hungary. The HoloVizio displays include 3D images on a monitor screen, allowing a viewer to walk around the screen in a wide field-of-view and see the objects and shadows moving continuously as in the normal perspective. Using a Holovizio display, it is possible see behind objects; while hidden details appear, others disappear (motion parallax). The displays are currently available in 32″ (16:9) and 26″ (4:3) screen sizes.
LightSpace Technologies, Inc. produces the DepthCube Z1024 3D display. LightSpace Technologies, Inc. is located at 26 Pearl Street, Norwalk, Conn. 06850, U.S.A. The DepthCube Z1024 3D display consists of 20 stacked LCD shutter panels, with video projected through the LCD shutters, thereby allowing viewers to see objects in three dimensions without the need for glasses. Unlike auto-stereoscopic displays, DepthCube technology doesn't limit the field-of-view, allowing multiple people to experience the 3D effect simultaneously.
The above techniques still have problems. For example, the Actuality Perspecta® display has very limited color and gray scales, limiting the display to show simple images only. Additionally, none of the currently available techniques allow for walk around displays.
Thus, a need exists in the art for a 3D display that allows a viewer to walk 360 degrees around the display and see a life size or reduced, 3D volumetric image in real-time.